1. Field of the Invention
The present invention relates to a device and methods for the destruction of noxious pollutants and contaminants. More particularly, it relates to a device and methods for the destruction of contaminants consisting of non-flammable, flammable, or combustion-inhibiting constituents which cause flameout of the direct flame. The device and methods described provide for destruction of as many as three different waste sources at the same time: 1) Volatile Organic Compounds (VOC's) and off-gas pollutants; 2) combustion products and noncombustible VOC's and contaminants; and (3) hydrocarbon liquids, wastewater or groundwater contaminated with contaminants such as MTBE, TBA, benzene, gasoline, or other similar compounds.
2. General Background and State of the Art
Hazardous materials and waste materials represent a serious challenge to human and animal health and to the environment as well. It is common to use thermal oxidizers or burner systems to destroy certain hazardous streams (such as streams containing VOC vapors, water vapor, high CO2, and low O2) through the use of high temperatures, known conventional burner systems employ heat transfer and minimal flame involvement that requires excessive retention times for destruction. Furthermore, the destruction efficiency of known burner systems results in marginal destruction efficiencies, which are less efficient in energy recovery from VOC's.
It has been found that improved methods of sustaining a high degree of mixing and turbulence is achieved through downstream perforated and nonperforated cones and other obstructions of varying types, which enhance the destruction and complete oxidation of pollutants.
As found in ‘ramjet’ combustion technology, the use of cones and downstream flame holders offer a greater degree of mixing and flame holding during the flame combustion operation, which has been shown in a wide range of aerospace ramjet and ram air burners used by the United States Department of Defense in recent years. It has been found that in practical applications, similar flame holding techniques through the use of downstream cones having baffles, orifices, slots, holes and other types of openings that produce an increase in mixing of the combustion products ensures a much higher degree of destruction and energy utilization than prior art systems. Furthermore, as found in ramjet and afterburners for defense applications; it has been shown that a direct correlation exists between the mass exchange rate in the recirculation zones of baffle flame holders and flame propagation rates, and the correlation indicates that the heat release rate in the wake behind these types of flame stabilizers controls the combustion rate downstream, which is also closely correlated to turbulence parameters and geometries.
There exists a need for a device and method of destroying vapors and/or liquids contaminated with hydrocarbons, chlorinated compounds, toxics and other volatile and non-volatile materials that are removed or are the result of various environmental cleanup, engine exhaust, industrial processes, and any other remediation procedures.
More specifically, there exists a need for a device and method that enables the destruction of hydrocarbon emissions and other contaminants that have elevated concentrations of those contaminants which may be difficult to destroy or are resistant to oxidation by ‘direct flame’ processing due to their inability to sustain combustion. These processes, such as those where high concentrations of CO2 and/or low O2 are present, as well as other constituents, inhibit ‘direct flame’ oxidation by snuffing out the flame propagation process by the nonflammable constituents present in the vapors that are to be destroyed.
There also exists a need for a device and method that achieves destruction of vapors through direct flame destruction and/or downstream secondary flame destruction, without the secondary flame destruction process impeding the destruction capability of the primary turbulent flame process in destroying VOC compounds.
There exists a need for a method whereby noxious vapors may be manually or automatically directed for direct flame or secondary flame destruction of the vapors, so that the method can be optimized for the application such that vapors that could or are likely to extinguish the flame by virtue of its constituents may be destroyed by either a combination of direct flame and/or downstream catalytic operation and/or secondary flame processing.
Furthermore, there exists a need for the integration of known turbulent combustion technologies (such as those found in U.S. Pat. Nos. 4,785,748 [Sujata, et al.], 5,381,659 [Loving], and 5,572,866 [Loving, et al.]) with a device and method that directs the flame process into maximizing contact with noxious vapors for either preheating, partial oxidation, or complete oxidation as required by the individual process needs and goals as mandated by air pollution regulations and agencies. The integration of existing technologies with split flows of vapors concurrently into the direct flame zone and a secondary flame zone, where the vapors are forced around and through items such as solid cones, perforated cones, nozzles or tubes enables much greater operating flexibility to achieve the desired effect of mixing and thereby achieving greater levels of destruction of noxious vapors for environmental cleanup and industrial applications.
There also exists a need for a device and method for the destruction of noxious emissions and combustion products found in diesel and Otto cycle engine processes that have elevated emissions levels of carbon dioxide, carbon monoxide, low oxygen levels, and noxious unburned or partially burned hydrocarbons. Such a process would enable either manual or automatic processing of these vapors either through a direct flame or a secondary, downstream flame destruction operation so as to not impede the continuous operation of the burner from flameouts that are likely to occur from the noncombustible characteristics of the influent noxious products of combustion.
There further exists a need for a device for destroying noxious vapors that is simple in operation, easy to maintain, and able to process varying vapor flows as required for the continuous destruction of varying compound concentrations.
There also exists a need for a device and method for the destruction and elimination of water vapor and accompanying contaminants in a manner that is energy efficient and provides for the atomization of water (or other liquids, including various hydrocarbons) in order to achieve heating of the water to a gaseous state prior to destruction as well as the destruction of any VOC's present in the vapor streams by direct flame or secondary flame pathways. Such a device would virtually eliminate water and VOC vapors contaminated with a wide variety of toxic compounds.
There also exists a need for a device and methods for processing multiple waste vapor and liquid streams at the same time by providing an extremely strong flame holder by creating numerous individual circulation zones and intimate and direct consumption of vapors and pollutants within these zones.
There exists a need for a device and methods for an “all-in-one” destruction capability of contaminants that result from environmental cleanup, remediation and compliance operations that will destroy 1) volatile organic compounds (“VOC's”) in the air, 2) VOC's extracted from water vapor, 3) VOC's and extracted groundwater, and 4) contaminants in industrial waste water.